全自动血液培养仪的质量控制

Quality control in automated blood culture system

目的:对BacT/Alert全自动血培养系统监测经 36℃孵育后进入系统的血培养瓶进行质量控制。 方法:采用在 FAN需氧培养瓶定量接种大肠埃希菌、伤寒沙门菌、铜绿假单胞菌、鲍曼不动杆菌和嗜麦芽窄食单胞菌,经℃,、、、360h4h8h和孵育后,进入系统监测,记录出现阳性信号的检出时间。16h24h结果:系统能在以内检出大肠埃希菌和伤寒沙门菌测6.8 h试瓶,不受进入系统前孵育时间影响;不能检出进入系统前孵育时间分别在和以上的铜绿假单胞菌、鲍曼不动杆菌测试 4h8h瓶和嗜麦芽窄食单胞菌测试瓶。系统检测进入系统前孵育时间为的大肠埃希菌测试瓶,不受其菌量影响;系统不能检出菌 8h量分别在及以上经℃孵育后铜绿假单胞菌和鲍曼不动杆菌测试瓶。 1200 cfu/ml 3400 cfu/ml 368h结论:延迟进入系统监测的血培养瓶,应盲目转种培养,避免漏检。

Objective: To determine whether preincubation would influence the detection capacity of the BacT/Alert blood culture system. Methods: The suspensions of the organisms to be tested (Escherichia coli ,Salmonella typhi, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii) were added to the ℃FAN aerobic blood culture bottles. They were loaded into the BacT/Alert system after incubation at 36 for 0h, ,4h, 8h 16h and 24h. The computer system would monitor the reflection units to signal positive to determine the detection time for the bottles. Results: All bottles seeded with E.Coli and S.typhi signaled positive during the next 6.8 h after loading into the BacT/Alert system. Organisms in bottles seeded with P. aeruginosa and A.baumannii were not detected by the system, even with shorter preincubation times, down to 4h.Organisms in bottles seeded with S.maltophilia were undetected with preincubation times longer than 8h,bottles failed to signal ℃positive for these species for 7 days. With an incubation time of 8h at 36, the bottles seeded with E.Coli signaled positive at each colony number tested. An inoculum of 1200 cfu/ml of P. aeruginosa, 3400 cfu/ml of A. baumannii remained undetected by the system for 7 days. Conclusion: Bottles which have been preincubated for 4h or longer should be subculture prior to loading to avoid false negatives.